A process of making paper using cationic starch complexes

ABSTRACT

Cationic starch complexes prepared by reacting an aqueous starch slurry with a water-soluble cationic polymeric polyelectrolyte are useful in treating cellulosic materials and as flocculating agents in aqueous systems.

O Umted States Patent 115:1 3,639,269 Buckman et al. 1 1 Feb. 1, 1972[541 A PROCESS OF MAKING PAPER USING [56] References Cited CATIONICSTARCH COMPLEXES UNITED STATES PATENTS [72] Inventors: Stanley J.Buckman; Richard W. Lutey;

George M. Jennings, a of Memphis 3,284,442 11/1966 Jarowenko et a1..260/233.5 Tenn 3,313,784 4/1967 Vrancken et a1 "260/2333 X 3,336,2928/1967 Kirby ..162/17S X [73] Ass1gnee: Buckman Laboratories, Inc.,Memph1s, 3 563 0/ 9 7 Shildneck et 31" 75 X 3,417,07s 12/1968 Patel etal. ..162/175 x [22] Filed: Apr. 7, 1970 Primary Examiner-ReubenFriedman [2]] App! 26434 Assistant Examiner--Frederick FreiAttorney--Floyd Trimble 1521 11.5.01 ..l62/l75,127/32,127/71, ABSTRACT It Cl 89 1 5 Cationic starch complexes prepared by reacting an aqueous l1l I [58 1 Field of Search ..l62/175; 127/32, 33, 71; starch Slurry 3water soluble ymem ye ec trolyte are useful in treating cellulosicmaterials and as flocculating agents in aqueous systems.

12 Claims, No Drawings PROCESS OF MAKING PAPER USING CATIONIC STARCHCOMPLEXES This invention relates to the art of cationic starch complexesand, more particularly, to cationic starch complexes which are obtainedby reacting starch with a water-soluble cationic polymericpolyelectrolyte.

Cationic starches, a class of specialty products of recent origin, havewithin a short period of time become very important commercially,particularly for use in the manufacture of paper. in papermaking, thesederivatives function very efficiently as internal binders, retentionaids for mineral fillers, and emulsifying agents for water-repellentsizes. Although cationic starches are three to four times as effectiveas conventional unmodified starches in improving paper strength, thepresent utilization of these derivatives represents only a smallfraction of the total amount of starch used in the manufacture of paper.This curtailed use has been due almost entirely to the premium price atwhich these products must be sold as a result ofhigh production costs.

Prior to our invention, cationic starch complexes have been prepared byan etherification process involving the introduction of basic nitrogengroups into the starch molecule. In general, suitable products ofthistype have been limited to two classifications, one of which isidentified as a tertiary aminoalkyl starch ether and the other as aquaternary ammonium alkyl starch ether. The tertiary derivative isprepared by reacting an alkaline starch slurry with Z-dimethylaminoethylchloride followed by acidification, while the quaternary derivative isprepared by reacting such a starch slurry with N-(2,3-epoxypropyl)-trimethylammonium chloride, also followed byacidification. The production of cationic starches through anetherification reaction not only requires the use of relativelyexpensive reagents but the efficiency of the process is severely limitedbecause of the necessity of forming a product which can be dewateredeasily as, for example, by filtration.

In addition to their use in the paper industry, the cationic starchcomplexes of the present invention are effective as drainage aids,formation aids, and retention aids in a wide variety of applicationssuch as spinning aids and antistatic agents for textile fibers andplastics. Furthermore, these complexes, particularly those prepared fromcationic polymeric polyelectrolytes having a relatively high molecularweight, are also useful as flocculants in the clarification ofincomingwater supplies and industrial and municipal effluents. We have foundthat when the compositions of our invention are used as flocculants,low'density flocs containing a large quantity of finely dividedparticles are formed. Although the rate of flocculation is slow informing such flocs, the overall result in papermaking and many otherapplications is desirable because under such conditions the loss ofvaluable solids is reduced to a minimum. The retention aid andflocculating properties of these polymers are very important in view ofthe attention now being given to stream pollution, as will be obviousfrom the following discussion.

Many methods have been proposed to alleviate the problems caused bystream pollution; none, however, have been entirely satisfactory.Obviously, complete retention of all particulate matter in the finishedproduct would eliminate all problems now caused by the discharge ofindustrial wastes into public waters. Complete retention, however,cannot be attained, so the best practical method is the retention ascompletely as possible of all particulate matter in the finishedproduct, thus reducing the amount of said particulate matter in thewater that is being discharged.

Reuse of process water is the next best method used by in dustry toreduce the pollution problem, but this procedure is only partiallysuccessful because continued reuse of process water increases theconcentration of the particulate matter as well as dissolved solids inthe water to such an extent that the water is no longer suitable forindustrial use. When this condition is reached, the process water mustbe either discharged as waste or the materials contained thereinrecovered and utilized or discarded. Since discarding the water as wasteis impractical and not permitted by most public authorities, it followsthat the removal ofthe materials contained in the water is mandatory. Inthe pulp and paper industry. the materials remaining in the processwater are valuable products and if not recovered, represent an economicloss. The cationic starch complexes of our invention are particularlyuseful in recovering these valuable products and thereby alleviatepollution problems of the pulp and paper-making industry.

The compounds of our invention can also be used to remove any solidparticulate matter remaining in the water before it is discharged, eventhough such matter is not of a character suitable for use but must bedisposed of by microbiological decomposition, combustion, or buried in asanitary fill.

The cationic starch complexes of this invention also are useful in thetreatment of incoming water in addition to the aforementionedapplications in industrial systems such as pulp and paper mills.Precipitation of the solids followed by filtration or settling has beenused to the greatest extent by industry for the treatment of incomingwater. Various flocculating agents have been proposed for this purposeincluding the well-known product alum. While alum is availableeconomically in adequate quantities, it is relatively slow acting and isnot an efficient flocculant for the finely divided solids that aregenerally present in industrial and municipal water supplies. Incontrast, the cationic starch complexes of this invention are fastacting flocculants. Since these complexes are compatible with alum, theycan be used as a supplement to low cost alum, thus achieving a reductionin process time plus the desired degree of completeness in the removalof finely divided solids from incoming water. Similar principles applyto the removal of particulate solid matter from water being dischargedas industrial or municipal effluents.

In addition to the use of the cationic starch complexes as summarizedabove, these compositions are useful in applications such asbacteriostatic agents, accelerators for curing various plastics,liquid-solid separation in gas scrubber water from steel blast furnaces,and the separation of tailings and fines from minerals in oreprocessing.

It is, therefore, a principal object of the present invention to providea new process for the production of cationic starch complexes whichobviates the disadvantages of the prior art processes for the productionof these products.

It is another object of our invention to provide cationic starchcomplexes that are useful in pulp and paper manufacturing as drainageaids, formation aids, retention aids, strength aids, and flocculants.

it is yet another object of this invention to provide new cationicstarch complexes for use in water treatment, capable of flocculatingundesirable ions and particulate matter so that said ions andparticulate matter may be removed from water supplies or renderedunobnoxious prior to initial use or reuse of the water.

These and other objects and advantages of the invention will appear asthe description proceeds.

To the accomplishment of the foregoing and related ends, this inventionthen comprises the features hereinafter fully described and particularlypointed out in the claims, the following description setting forth indetail certain illustrative embodiments of the invention, these beingindicative, however, ofbut a few of the various ways in which theprinciples of the invention may be employed.

In brief, the foregoing objects and advantages are attained by use of acationic starch complex prepared, preferably shortly before itssubsequent use, by reacting an aqueous starch slurry with awater-soluble cationic polymeric polyelectrolyte in an amount varyingfrom 2. to 25 weight percent, preferably 5 to 10 weight percent of thepolyelectrolyte based on the dry weight of the starch. Thepolyelectrolyte is prepared by reacting a dihalo organic compound with asecondary or ditertiary amine. Suitable dihalo organic compounds arethose having the formula:

wherein X represents Br or Cl; Y represents a Cl-l group and/or asubstituted CH group wherein one of the hydrogens thereof is replaced byalkyl or hydroxylmethyl; and m and n independently represent integersvarying from 1 to 10.

O H Z represents O-, -l I, CHzCHz0-, OCH-CHzO, OCH:O, -S-, S 0, and S0:.

When Y represents a substituted CH group or represents bothunsubstituted and substituted CH groups, the total number of substitutedCH groups may not exceed 3.

Also stated briefly, when the cationic starch complexes of our inventionare used as a papermaking aid, one or more are added continuously to thepaper machine system at suitable locations such as the machine chest,the fan pump, or the headbox. Furthermore, we have found that the starchcomplexes of this invention may be added to the papermaking systemproducing various types of paper and paperboard with highly beneficialresults. Broadly stated, the desirable results obtained by following theteachings of this invention may be summarized as follows:

1. Increased production per unit of equipment 2. Improved formation andstrength properties of paper and paperboard 3. lncrease in overall millefficiency in that losses of fines such as fine fibers, pigments,fillers, and other paper components are minimized by increasingretention of these products in paper and paperboard.

4. Alleviation of water pollution problems When these products are usedas flocculants, one or more may be added to a given aqueous suspensionwith sufficient agitation to insure uniform Following this treatment,the flocculated aggregates will settle.

The amount of the products of this invention necessary to produce thedesired result is highly variable depending on the amount and nature ofthe particulate matter on which an effect is needed as well as the othercomponents of the ionic environment in which the starch complex andparticulate matter are present. Suitable and preferred quantities of theproducts of this invention when used in papermaking processes vary from0.05 to 5.0 weight percent and 0.5 to 2.0 weight percent, respectively,based on the dry weight of the papermaking components. When used inwater treatment processes, suitable and preferred quantities of theproducts of this invention vary from 0.5 to 25 parts and 0.5 to 5.0parts, respectively, per million parts of water and particulate matter.

Before proceeding with specific examples illustrating our invention, itmay be well to indicate in general the nature of the material required.Suitable starches for use in this invention include any of theconvention starches available commercially such as those derived fromcorn, wheat, potato, tapioca, waxy maize, sago', rice, sorghum,arrowroot, and high amylose corn as well as the amylose and amylopectinfractions of any of the latter starch sources.

Since the reaction between the dihalo compound and the amine isequimolecular, we generally prefer to employ these two reactants inapproximately equal molecular proportions in preparing the cationicpolymeric polyelectrolytes used in our invention.

Examples ofsuitable dihalo organic compounds which have been used in thepreparation of the polymeric compounds include: Bis(chloromethyl) ether,bis-(2-chloroethyl) ether, bis(2-chloropropyl) ether, bis(4-chlorobutyl)ether, oxy-3,3- bis(2-chloropropanol-1 bis(Z-chloroethyl) sulfide,bis(2- chloroethyl) sulfoxide, bis( 2-chloroethyl) sulfone, bis(3-chloropropyl) sulfide, bis(Z-chloropropyl) sulfone, bis(2-chloroethoxy)ethane, 1,2-bis(chloromethoxy)-ethane, 1,2-bis(2-chloroethoxy)ethane, 1,2-bis(2-chloroethoxy)propane, I,2-bis-(2-chloropropoxy)propane, 1,3-dichloropropanone-2,

morpholine, 2,6-dimethylmorpholine, 1,2,4-trimethylpiperazine, andl,4-bis( 2-hydroxypropyl)-2-methylpiperazine.

In general the ditertiary amines are preferred as the dihalo organiccompounds react directly with such amines to form a polyquaternaryproduct. If a secondary amine is used, the dihalo compound reacts withthe amine to form a ditertiary amine salt which upon neutralizationundergoes polymerization with an additional quantity of the dihalocompound. The reaction between the dihalo compound and the amine isconducted in the presence of an inert solvent, preferably water. Asuitable reaction temperature varies from 50l 50 C.

In order to disclose the nature of the present invention still moreclearly, the following illustrative examples will be given wherein partsare parts by weight. It is to be understood, however, that the inventionis not to be limited to the specific conditions or details set forth inthese examples except insofar as such limitations are specified in theappended claims.

EXAMPLE 1 A 300-gallon stainless steel reactor fitted with a stirrer wascharged with 317 parts of N,N,N',N'- tetramethylethylenediamine, 392parts of dichloroethyl ether, and 381 parts of water. The contents werestirred and hot water was introduced into the jacket. The temperaturewas maintained at 93-l02 C. for a period of 16 hours. At the end of thisperiod, the resulting polymer solution (polymer plus water) was cooledand removed from the reactor. The polymer had a reduced viscosity of0.3,wherein reduced viscosity is defined as the specific viscositydivided by the concentration in grams per milliliters. ln all examples,a concentration of 0.2 gram of polymer per 100 milliliters of water wasused to determine the reduced viscosity.

EXAMPLE 2 A 250-milliliter three-necked, round-bottom flask equippedwith stirrer, addition funnel, and thermometer was charged with 50.0grams (0.432 mole) of N,N,N,N'- tetramethylethylenediamine, 61.8 grams(0.432 mole) of dichloroethyl ether, and 60 grams of water. Thereactants were stirred and heated at 100 C. for 18 hours. At the end ofthis period, the resulting polymer solution was cooled and removed fromthe flask. The polymer had a reduced viscosity of 0.3.

EXAMPLE 3 The procedure of example 2 was followed with the exceptionthat 80.7 grams (0.432 mole) of l,2-bis(2-chloroethoxy)ethane wassubstituted for the dichloroethyl ether. The amount of water used inthis example was 70.3 grams. At the end of the reaction period, thepolymer solution was viscous and lightucolored. The polymer had areduced viscosity of 0.3.

EXAMPLE 4 The procedure of example 2 was again followed wherein 35.0grams (0.306 mole) ofN,N-dimethylpiperazine was substituted for theamine used in example 2 and 43.4 grams (0.306 mole) of dichloroethylether was the specific dihalo compound used together with 41.9 grams ofwater. The

polymer so obtained was dark red having a reduced viscosity of 0. 1 5.

EXAMPLE 5 The procedure of example 2 was again followed wherein 35 grams(0.20 mole) of 1,4-bis(chloromethyl)benzene, 23.2 grams (0.20 mole) ofN,N,N,N'-tetramethylethylenediamine, and 41.3 grams of water were used.The polymer solution was a light-colored viscous liquid. The polymer hada reduced viscosity of 1,7.

EXAMPLE 6 The procedure of example 2 was again followed in which 62.5grams (0.432 mole) of N,N,N,N'-tetramethyl-l,3-butanediamine and 61.8grams (0.432 mole) of dichloroethyl ether in 61.2 grams of water werereacted at 100 C. for 18 hours. The polymer solution so obtained waslight colored but very viscous. The polymer had a reduced viscosity of0.4.

EXAMPLE 7 The procedure of example 2 was again followed in which 1 1grams (0.0629 mole) of l,4-bis(chloromethyl)benzene, 4.35 grams (0.629mole) of an aqueous 60percent dimethylamide solution, and 2.52 grams(0.063 mole) of sodium hydroxide mixed with 6.73 grams of water werereacted for 18 hours at 100 C. The polymer mixture so obtained was asolid. The polymer had a reduced viscosity of 0.40.

EXAMPLE 8 EXAMPLE 9 The procedure of example 2 was again followed inwhich 50 grams (0.229 mole) of 1,3-dibromo-2-propanol, 26,6 grams (0.229mole) of the amine used in example 3, and 76.6 grams of water werereacted for 18 hours at 100 C. The polymer had a reduced viscosityofless than 0.1.

All of the polymers prepared according to examples 4 to 10 as well asthose prepared from the foregoing lists of dihalo organic compounds andamines were found to be effective flocculants.

EXAMPLE 10 Preparation of a cationic starch complex A reactor equippedwith a stirrer, thermometer, and means for heating was charged with67.55 parts of water, 30 parts of pearl starch, and 3.00 parts of thepolymeric polyelectrolyte of example 1 dissolved in 2.45 parts of water.The reactants were stirred and heated at 195 F. for minutes. At the endof this period, the resulting product was diluted with sufficient waterto reduce the concentration ofstarch solids to 3 percent.

EXAMPLE 11 In this example, two runs were made:

Run No. 1 was a conventional process for the production of newsprint ona fourdrinier machine from an aqueous slurry of cellulosic materialscontaining the usual papermaking additives. To improve the lintingcharacteristics of the paper. a commercial cationic starch was added tothe furnish at the fan pump at a rate equal to 7 pounds of starch perton of paper produced.

Since the art of papermaking is well! known by those skilled in thisfield, a description of such a process will not be repeated here. For adetailed description thereof, reference is made to any standard text onthe subject. Two such references are Sven A. Rydholm, PulpingProcesses," lnterscience Publishers, New York, London, and Sydney, 1965,particularly pages 1135-1166, and Pulp and Paper Science and Technology,Vol. 11 Paper, edited by C. Earl Libby, McGraw- Hill Book Co., New York,1962, particularly chapter 7 thereof, which references are hereby made apart of this application.

Run No. 2 was a duplicate of run No. 1 with the exception that an equalquantity of treated corn starch was substituted for the cationic starch.In preparing the treated corn starch used in this run, the product ofexample 1 was added with stirring to an aqueous slurry of corn starch inan amount equivalent to 10 percent based on the dry weight of cornstarch. After the two components were admixed, the mixture was heated to190 F. and maintained at that temperature for 5 minutes. The treatedcorn starch was then added to the furnish at the fan pump.

Test results revealed that the linting characteristics of the two paperproducts so produced were equivalent. in addition, sheet strength andash content of the paper from run No. 2 were both higher than that ofthepaper from run No. 1.

EXAMPLES 12-18 In these examples, the procedure of example 11 wasrepeated with the exception that the products of examples 3-9 wereindividually substituted for the product of example 1 in preparing thetreated corn starch which was subsequently used in the papermakingprocess. The results were similar to those obtained in example 1 1.

Similar results were obtained when wheat, potato, tapioca, waxy maize,sago, rice, sorghum, and a'rrowroot starches were substituted for thecorn starch used in examples 1 ll8.

EXAMPLE 19 in this example, two runs were made:

Run No. 1 was a conventional process for the production of linerboard ona fourdrinier machine from an aqueous slurry of cellulosic materialscontaining the usual papermaking additives. In this run, locust bean gunused in conjunction with the product of example 1 was added to thefurnish at the fan pump to give paper of the desired strength.Specifically, pounds of gum and 7.1 pounds of the product of example 1diluted with 1,500 gallons of water were added to the system at a rateof 40 gallons per minute. This corresponds to about 3.5 pounds per tonof paper.

Run No. 2 was a duplicate of run No. 1 with the exception that 200pounds of tapioca starch was substituted for the 100 pounds of gum andthe quantity of the product of example 1 was reduced to 4.77 pounds from7.1 pounds. As in run No. l, the two components were diluted with 1,500gallons of water and then added to the system. When the resultingmixture was added at a rate of 20 gallons per minute. the paper soproduced had the same strength as that produced in run No. 1.

Similar results were obtained when the products of examples 3-9 wereindividually substituted for the product ofexampie 1 as described inruns No. 1 and 2 above. We also found that corn, wheat, potato, waxymaize, sago, rice, sorghum, and arrowroot starches could be used insteadof tapioca starch with equivalent results.

EXAMPLE 20 The flocculating ability of the cationic starch complexofexample 10 was determined by use of a "jar test" in which an aqueousmixture containing 150 parts of air-dried paper fiber and 250 parts of apredispersed clay per million parts of water was treated with variousamounts of alum and the cationic starch complex. In this example, thecomplex was diluted with water to make up a solution containing varyingamounts of the complex, and then added with gentle stirring plus thealum to the suspension of clay and fiber. Comparable results were alsoobtained in similar systems containing suspensions of clay and fiberwithout alum. After mixing, the results were rated visually on the basisof the following key:

=n0 apparent flocculation l =some flocculation 2 =most of the turbidityremoved 3 =complete flocculation, water essentially clear pH 5 pH 9 1 53O 1 5 3O Alum 1 Complex 1 min. min. mln. min. min. min.

0 0 0 U 0 0 0 0 0 1. 0 0 l 1 0 0 0 0 2. 0 1 1 l 0 0 ll 0 5. 0 1 2 2 ,1 11 0 10. O 2 2 2 2 2 2 0 20. 0 2 2 2 l 1 1 0 0 0 1 1 0 0 0 40 0 1 2 2 1 22 40 1. 0 3 3 3 1 l 1 40 2. 0 2 3 3 2 3 3 40 10. 0 3 3 3 2 3 3 40 20. 03 3 3 2 3 3 i Pounds per air-dried ton of clay-fiber.

While particular embodiments of the invention have been described, itwill be understood, of course, that the invention is not limited theretosince many modifications may be made, and it is, therefore, contemplatedto cover by the appended claims any such modifications as fall withinthe true spirit and scope of the invention.

The invention having thus been described, what is claimed and desired tobe secured by Letters Patent is:

1. In a process for the production of paper wherein an aqueous fluidcontaining cellulosic pulp and other papermaking ingredients is formedinto a sheet on a fourdrinier wire cloth, the improvement whichcomprises adding to said aqueous fluid before the furnish contacts saidfourdrinier wire cloth a cationic starch complex prepared by reacting anaqueous starch slurry with a water-soluble cationic polymericpolyelectrolyte in a ratio of from 0.02 to 0.25 parts by weight of thepolyelectrolyte per part of starch, said polyelectrolyte formed byreacting in approximately equimolecular quantities a dihalo organiccompound having the formula wherein X represents Br or Cl; Y representsa CH- group or a CH, group wherein one of the hydrogens thereof isreplaced by alkyl or hydroxymethyl, characterized in that the totalnumber of substituted CH groups of each Y may not exceed 3, m and nindependently represent integers varying from 1 to 10,

with a secondary or a ditertiary amine in the presence ofa solvent, inan amount sufficient to improve the papermaking process and the paperand paperboard produced thereby.

2. The process of claim 1 wherein the dihalo organic compound isl,2-bis( 2-chloroethoxy)ethane.

3. The process of claim 1 wherein the dihalo organic compound isdichloroethyl ether.

4. The process of claim 1 wherein the dihalo organic compound is l,4-bis(chloromethyl)benzene.

5. The process of claim 1 wherein the cationic starch complex used insaid process is formed by reacting an aqueous starch slurry with awater-soluble cationic polymeric polyelectrolyte in a ratio of from 0.02to 0.25 parts by weight of the polyelectrolyte per part of starch, saidpolyelectrolyte formed by reacting in approximately equimolecularquantities a dihalo organic compound having the formula:

X-(Y),,,-Z-(Y),,-X wherein X represents Br or C1; Y represents a CHgroup or a CH. group wherein one of the hydrogens thereof is replaced byalkyl or hydroxymethyl, characterized in that the total number ofsubstituted CH groups of each Y may not exceed 3; m and N independentlyrepresent integers varying from 1 to l0, n

6. The process of claim 5 wherein the polyelectrolyte is formed byreacting a dihalo organic compound with N,N- dimethylpiperazine.

7. The process of claim 5 wherein the polyelectrolyte is formed byreacting a dihalo organic compound with N,N,N',N-tetramethyl-l,3-butanediamine.

8. The process of claim 5 wherein the polyelectrolyte is formed byreacting a diahlo organic compound with dimethylamine.

9. The process of claim 5 wherein the starch used in preparing thecationic starch complex is corn starch. I

10. The process of claim 5 wherein the starch used in preparing thecationic starch complex is tapioca starch.

11. The process of claim 5 wherein the starch used in preparing thecationic starch complex is wheat starch.

12. The process of claim 5 wherein the starch used in preparing thecationic starch complex is potato starch.

V with If{-t etrametlrylethylencdiamine.

2. The process of claim 1 wherein the dihalo organic compound is1,2-bis(2-chloroethoxy)etHane.
 3. The process of claim 1 wherein thedihalo organic compound is dichloroethyl ether.
 4. The process of claim1 wherein the dihalo organic compound is 1,4-bis(chloromethyl)benzene.5. The process of claim 1 wherein the cationic starch complex used insaid process is formed by reacting an aqueous starch slurry with awater-soluble cationic polymeric polyelectrolyte in a ratio of from 0.02to 0.25 parts by weight of the polyelectrolyte per part of starch, saidpolyelectrolyte formed by reacting in approximately equimolecularquantities a dihalo organic compound having the formula: X-(Y)m-Z-(Y)n-Xwherein X represents Br or C1; Y represents a CH2 group or a CH2 groupwherein one of the hydrogens thereof is replaced by alkyl orhydroxymethyl, characterized in that the total number of substituted CH2groups of each Y may not exceed 3; m and N independently representintegers varying from 1 to 10, n
 6. The process of claim 5 wherein thepolyelectrolyte is formed by reacting a dihalo organic compound withN,N''-dimethylpiperazine.
 7. The process of claim 5 wherein thepolyelectrolyte is formed by reacting a dihalo organic compound withN,N,N'',N''-tetramethyl-1,3-butanediamine.
 8. The process of claim 5wherein the polyelectrolyte is formed by reacting a diahlo organiccompound with dimethylamine.
 9. The process of claim 5 wherein thestarch used in preparing the cationic starch complex is corn starch. 10.The process of claim 5 wherein the starch used in preparing the cationicstarch complex is tapioca starch.
 11. The process of claim 5 wherein thestarch used in preparing the cationic starch complex is wheat starch.12. The process of claim 5 wherein the starch used in preparing thecationic starch complex is potato starch.